DESCRIBING THE AFTERMATH of Hurricane Katrina in New Orleans is difficult because it involves such a massive scale of destruction. But imagine it this way, and perhaps you’ll get some sense of things.

Let’s assume the town where you live just suffered the same kind of catastrophe. You decide to go for a walk to assess the damage. How bad is it? Well, every house on your street is abandoned. All the trees are dead (even those still standing); so are the bushes, lawns, shrubs, and any other landscaping. The streets around you are littered with debris—furniture, bedding, clothes, large and small appliances, art, books, personal papers. Cars sit in driveways, on sidewalks, in yards, on trees, on top of each other, anywhere and everywhere. They’re covered, inside and out, in a fine layer of silt, and they stink. The streets are covered in the same toxic grime. So are the yards, which